Table 1.

Summary of gene therapy approach by herpes simplex virus–mediated glutamic acid decarboxylase for chronic pain in animals models

Animal Models	Genes	Routes of HSV Delivery	Results	References
Rat SCI	GAD67	Hind paw injection	Reduced mechanical allodynia and thermal hyperalgesia at 1–6 weeks postinfection; bicuculline reverses the antinociceptive effect	23
Rat SCI	GAD67	Bladder wall injection	Decreased number and amplitude of nonvoiding contractions, which was reversed by bicuculline	26
Rat SNL	GAD67	Hind paw injection	Reduced mechanical allodynia and thermal hyperalgesia and suppressed spinal c-fos and pERK1/2	27
Rat ligation of lumbar roots	GAD67	Hind paw injection	Reduction in mechanical allodynia	28
Rat sciatic gp120	GAD67	Hind paw injection	Reduced mechanical allodynia at 3–28 days postinfection; bicuculline/CGP54626 reversed the anti-allodynic effect; decrease spinal ROS and Wnt5a	51
Rat sciatic gp120+ddC	GAD67	Hind paw injection	Reduced mechanical allodynia at 3–28 days postinfection; decrease spinal ROS, pCREB, pC/EBPβ	56
Rat PDN	GAD67	Hind paw injection	Reduced mechanical hyperalgesia, thermal hyperalgesia, and cold allodynia and lowered the voltage-gated sodium channel isoform 1.7	61
Mice and rat PDN	GAD65, GAD67	Hind paw injection	Reduced mechanical allodynia and thermal hyperalgesia	62

GAD, glutamic acid decarboxylase; HSV, herpes simplex virus; PDN, painful diabetic neuropathy; pERK1/2, phosphorylated extracellular signal-regulated kinase 1/2; ROS, reactive oxygen species; SCI, spinal cord injury; SNL, spinal nerve ligation; Wnt5a, Wingless-Type Mammary Tumor Virus Integration-Site Family Member 5a.